Maybe. As far as I know, he was born in Siberia, though. He might have had Ukranian ancestors. But I do have a few more names to add. Kuusinin, who was Finnish, was a member of the Politburo. So was Masherov, who was Belarussan. More recently, Alfreds Rubiks is Latvian, Aram Sariksyan, I’m betting, is Armenian. There was also Enn-Arno Sillari, and Lembit Annus, both of whom were, I think, Estonian.
There are some, largely unfounded, theories that Stalin was actually Ossetian and not Georgian, putting him into even smaller ethnic group. These theories are generally claimed only by Ossetians themselves, though.
It should be remembered that while Russians clearly were overrepresented in high places of the party, they made up almost half of the population of Soviet Union, thus it’s no wonder that they always were the biggest group there. And since the country had such massive inner inequalities, families in Moscow, Leningrad and other densely populated majorly Russian areas were always richer and better educated with higher chances of being successful than others who were from Central Asia, Caucasus, Siberia and other non-Russian regions.
Leon Trotsky, whose real name was Lev Bronstein, was 100% Jewish and an early Bolshivek leader who formed and headed the Red Army. He was also a founding member of the Politburo.
Lenin himself was of half Russian ancestry, but he was also one-quarter Jewish. His maternal grandfather, Israel (Alexander) Blank, was a Ukrainian Jew who was later baptized into the Russian Orthodox Church.
A great, great deal has anti-semitically been made of this (& of Trotsky’s jewishness) – if Lenin had any Jewish “identity” it has not documented.
Lenin also had as much Volga German ancestry through his mother, who was a Lutheran. Much less has been made of this.